Triterpenoid saponins, new metalloprotease snake venom inhibitors isolated from Pentaclethra macroloba - Silva, Jocivânia O. da; Fernandes, Renata S.; Ticli, Fábio K.; Oliveira, Clayton Z.; Mazzi, Maurício V.; Franco, João José; Giuliatti, Silvana; Pereira, Paulo S.; Soares, Andreimar Martins; Sampaio, Suely Vilela (Toxicon, 2007)